Process of making drawing instruments



July 15 1924. 1,501,169

' A. W KEUFFEL PROCESS of MAKING DRAWING INSTRUMENTS Filgd April 24, 1922 CW-ao 555 .3 Mg: 3 T1g4: d ?1g l8' g a? mi iaz 28 3";

Patented July 15 i924;

ADOLF W. KEUFFEL, OF MONTCLAIR, NEW JERSEY, ASSIGNOR TO KEUFFEL 8r, ESSER COMPANY, OF HGBQKEN, NEW JER-SEY,A CORPORATION OF NEV! JERSEY.

PROCESS OF MAKING DRAWING- INSTR-UIVIENTS.

Application filed April 24, 1922.

To all whom it may concern:

Be it known that I, ADoLr W. IEUFFEL7 a citizen of the United States, residing at 763 Bloomfield Avenue, in the township of Montclair, in the county of Essex and State of New Jersey, have invented certain new and useful Improvements in the Process of Making Drawing Instruments, of which the following is a specification.

This invention relates to the process of making drawing instrument legs, and the novelty consists in the steps of the process, as will be more fully hereinafter pointed out.

Under former methods of manufacture it was necessary to take solid blanks of metal large enough to include the hinge or shoulder portions of the separate legs, and by milling and a long tedious process cutting away the metal so as to form the legs with shoulder or hinge portion attachments as required. I

My method has eliminated the necessity of milling and makes use of a blank of substantially the cylindrical form required, which is quickly andeasily tapered to the exact form required by means of the use of a screw machine, thereby effecting a new cylindrical shape for the legs which is most desirable, and accomplishing this with very slight labor and very material saving in i'nanufacturmg cost. The shoulder or hinge portion is then formed separately and brazed to the leg, and a clamping means for a needle or a pencil point is also separately brazed to'the leg, thereby eliminating the necessity of using a metal blank of large proportions and cutting it down so as'to include said shoulder and clamping means. In my process I first harden the needle as required for final use and then drive it into the driveiit boring in the lower end of the leg, thereby eliminating any necessity for hardenin after the needle has been driven into sai lieferring to the drawings Figure 1 is a top plan view of a cylindrical blank adapted for use in my process; Figure 2 is an end view of Figure 1; Figure 3 is a top plan View of an upper leg which has been formed from the blank of Fig. 1; Figure 4 is an end view of the same looking in from the righthand end; Figure 5 is a top plan view of the shoulder or hinge member; Figure 6 is the same as Figure 3, but with the shoulder of Serial No. 556,132.

Figure 5 brazed thereto; Figure 7 is an end view of Figure 6 looking in from the right hand end; Figure 8' is an end view of 9 looking in from the left-hand end; Figure 9 is a side elevation of a lower leg of the drawing instrument; Figure 10 is an end view of F 9 looking in from the righthand end; Figure 11 is an end elevation of the clamping blank; Figure 12 is a side elevation of the clamping blank shown in Fig. 11; Figure 13 is the same as Fig. 9, but with the clamping blank brazed thereto and bored; Figure 141- is a top plan view of Fig.

13 in which the lower end oi the leg has been sawed; Figure is another form of drawing instrument leg having a boring at the lower end to receive a needle point, and with the upper portion of the leg broken away for convenience in illustration; Figure 16 is a top plan View of the needle point adapted to be mounted in the leg shown in Fig. Figure 17 is the same as Figure 15, but with the needle point of Fig. 16 mounted'therein; and Figure 18 is top plan view or" the lower end of an upper leg having a mouth adapted to receive the tongue of the lower leg, the upper-portion being broken away for convenience inillustration.

In carrying out my process a-cylindrical blank 20 of nickel silver, or of any metal of a similardegree of density and hardness, is

cut to the desired length, as shown in Fig? l; -Thebla'nk 20 is then tapered by means of a screw machine to the exact sizerequifed, as shown inFig. 3; The taper turning de-' vice made by and adapted to beattached'to the Brown & Sharpe Mfg. Co. automatic lathe embodies such a Well knownscre'w machine. In this machineithe taper turning device, in which a lathe tool is'mounted is attached in one of thesix holes of the turret and the. tool comes into position at a-certainspecified time controlled by means of the cams of the machine at each cycle. As the turret is driven along the axis of the machine the lathe tool in the taper turning device turns whatever shape is desired on the raw material in the revolving chuck of the machine. This is one of the many different Well known screw machines on the market. A curved shoulder 21 is then cut therein, and a circular groove 22 is cut therein to facilitate in the handling of the instrument and the small end is tapered at 23, thereby forming the leg 2%; For certain of my c rawing instrui'uents I then cut a mouth 29 in the base of the leg 24 with a deeper slot 30 in the base of said mouth 29, thereby torn ing two spring gripping members 31. l. snoulder or hinge member 20, circular in :t'orm and having a bevelled edge 26 and a flat portion 27 adapted to fit a curved shoulder 21 of the leg 24:, is-made separately. The shoulder or hinge member 25 is then brazed to the shoulder 21 or the leg 2%, so that the flattened portion 2? lies in the curved shoulder portion 21.

A lower leg is shown in Figures 8 to ll, inclusive, in which a leg 28 has a cylindrical shoulder 32 and a tongue 33, both of which are made integral there *ith. A metal blank having an are 35 at its base is adapted to be brazed near the lower end of the leg 28, the arc 35 being adapted to lit the leg 28, and the blank 34; is thenbored at 36, and the lower end or the leg 28 is then sawed so as to form an opening therein at 37, which cut passes through the blank 34 as is'shown in Fig. 14. here it is desired to mount the needle directly in the leg I harden a needle 38 to the degree desired for actual use and drill a hole 40 in a leg 39 so that the hole 40 is a snug lit for the needle 38, and I then drive the needle 38 in the hole 40 in the usual well-known manner.

In carrying out my process a long cylindrical blank may also be used, and this may be tapered as described, and the length required for a leg is then cut and the remaining blank portion again tapered and cut until the blank is used up.

I claim: c

1. The process of making a drawing instrument upper leg consisting of cutting a cylindrical metal blank to the length of up per leg desired, tapering the same to size required by means of a screw machine, cutting out a curved shoulder at the larger end, brazing a separately made shoulder menr her to said curved shoulder and cutting a groove in the lower end of the said leg adapted to receive a tongue of a lower leg.

2. The process of making a drawing instrument leg consisting of cutting a cylindrical metal blank to the length of the leg de sired, tapering the same to size required by means of a screw machine, cutting out a curved shoulder at the larger end, brazing a separately made shoulder member to said curved shoulder, and drilling a hole in the lower end of said leg, and driving into same a previously hardened needle.

3. The process of making a drawing instrument upper leg consisting of cutting a cylindrical metal blank to the length of up per leg desired, tapering the same to size required by means of a screw machine, cutting a circulargroove at about the middle of said leg, cutting out a curved shoulder in the larger end of said leg, brazing a separately made shoulder member to sa i d curved shoulder and cutting a groove in the lower end or the said leg adapted to receive a tongue of a lower leg.

l. The process of making a drawing instrument leg consisting of cutting a cylindrical metal blank to the length of leg desired, tapering the same to size required by means of a screw machine, cuttingacircular groove at about the middle of said groove, cutting out a curved shoulder at the larger end, brazing a separately made shoulder member to said curved shoulder, and drilling a hole in the lower end of said leg and driving into same a previously hardened needle.

5. The process of making a drawing in strument lower leg consisting of cutting a cylindrical metal blank to the length of lower leg desired, tapering the same to the size required by means of a screw machine, culling a cylindrical shoulder and tongue at the larger end of same, brazing a metal blank having a base adapted to fit said leg to the lower end of said le boring a hole through said blank transversely to the longitudinal axis of said leg, and sawing said blank and lower end of leg on the longitudinal axis of said leg.

6. 'lne process of making a drawing instrument leg consisting of tapering a portion of a long cylindrical metal blank to the length of leg desired by means of a screw machine, cutting the same to the length desired, cutting a shoulder at the larger end of said leg and securing a separately made shoulder member to said leg shoulder.

In testimony whereof I afiix my signature.

ADOLF W. KEUFFEL. 

